Metal fusing apparatus



'Feb. 9, 1943. R. K. HOPKINS I METAL FUSING \PPARATUS Filed Sept. 27,1941. 2123 24 2 Sheets-Sheet 1 ROBERT K. HOPKINS INVENTOR ATTORNEY Feb.9, 1943.

R. K. HOPKINS 2,310,635

METAL FUSING APPARATUS.

Filed Sept. 27, 1941 2 Sheets-Sheet 2 ROBERT K. HOPKINS INVENTORATTORNEY Patented Feb. 9, 1943 UNITED sm'rlazs PATENT OFFICE- METALFUSING arranaros- Robert K. Hopkins, New York, N. Y.; assignor to The M.W. Kellogg Company, New York, N.

. a corporation of Delaware Application September 27, 1941, Serial No.412,511

9 Claims. (Cl. 13-9) This invention relates to the production of metaland in particular to apparatus for the continuous production of metal.

I have heretofore disclosed a method for continuously producingmetal-in'which the constituents of the desired metal are supplied in thenecessary proportions and at constant rates into a'fusion zone whereinthey are continuously con: verted into the desired metal. The desiredmetal .thu's produced is continuously removed from the fusion zone atthe rate at which it is produced. The operating conditions are soadjusted and controlled that the desired metal withdrawn from the fusionzone is of constant character and analysis.

It is a primary object of this invention to provide novel apparatus,especially adapted for use in the continuous production of metal, whichis of eral application is especially adapted for usein continuous metalproducing operations. The apparatus of the invention maybe used withvarious sources of heat such as the electric arc, electric induction,the gas flame, etc. Also, the raw materials that are required for theproduction of the desired metal may be supplied in various ways. Forthe-purposes of this application the novel apparatus is disclosed in aninstallation that employs the electric are as the heat source andsupplies the raw materials required by means of and through a hollowmetal electrode. A. C. or D. 0. current may be used.

The apparatus installation shown includes a support ll, formed ofstructural members, provided with horizontal members ll upon which abridge I2 is mounted for movement. A truck I3 is mounted for movement onbridge l2. By

simple construction and is so arranged that the essential conditions ofthe metal producing operation may be easily and accurately adjusted andmaintained.

It is also one of the important objects of this invention to providenovel apparatus, especiallyadapted for use in the continuous productionof metal, which includes simple, removable arrangements capable ofadjustment for maintaining desired depths of molten materials in thefusion zone; the arrangements being such that they do not deterioraterapidly in use and when worn can be easily and conveniently replaced.

It is a further object of the invention to provide novelapparatus,.especi ally adapted for use in the continuous production ofmetal, which includes a simple arrangement for preventing thedestruction of the refractory lining of the fusion zone when theapparatus is allowed to cool to normal temperatures after use. I

The further objects and advantages of the invention will be betterunderstood from a consideration of the following description of apresent preferred embodiment of the invention taken with theaccompanying drawings, in which:

Fig. 1 is a front view of an apparatus assembly which includes a presentpreferred form of the apparatus of the invention,

Fig. 2 is a plan .view of the lower portion of the apparatus, x

Fig. 3. is a sectional view taken on line 3-3 of Fig. 2; in this figurethe apparatus is shown as it appears in operation,

Fig. 4 is a fragmentary sectional view corresponding to Fig. 3 showingamodiflcation, and

Fig. 5 is a front view of a skimmer element. The apparatus of theinvention while of genmeans of this arrangement truck is may be moved inany horizontal direction.

An electrode forming and feeding mechanism I4 is supported on truck l3and is movable vertically, manually or by motor operated means, relativetotru'ck IS. The mechanism ll includes a plurality of rollers l5 whichare adapted to form a flat strip [6, supplied by a coil ll alsosupported on truck l3, into a hollow electrode l8. Rollers I5 are drivenby a variable speed motor which is are controlled, as is common in theelectric arc welding and electric arc furnace art, to form and feedelectrode I8 as required to maintain an electric discharge ofsubstantially constant characteristics from its end. In this way asubstantially constant predetermined rate of fusion of electrode l8 maybe obtained. If preferred, for the same purpose, electrode l8 may be fedat a constant rate, equal to the desired rate of burnoif, and thecurrent supply adjusted to burn electrode l8 at the rate supplied.

Electrode it passes through a contact device l9 whichis supportedfrommechanism H. A cable 2| connects device H to one side of theelectric current supply which may be a-generator or a transformencarriedon truck I; or elsewhere on or near the apparatus, or a connection to anoutside current source.

Strip it, out of which electrode I8 is formed, is made of one of the rawmaterials used to supply the constituents of the desired metal. Whenproducing ferro-alloys whose major constituent is iron, strip [6 canconveniently be Armco ironthrough rollers into electrode l8.

' con be supplied at constant rates to the are at the end stitutedforcoils 94.

. A be t:inade of one,or more, of the other constituen v a u i A housing2| is supported above mechanism i4 and in it are positioned a pluralityof metering devices. The metering devices and housing It are movablewith mechanism It. Each metering device is arranged toreceive materialin the'g'ranular' form from a hopper, such as hoppers 22, 23 e and 24,and feed it at a constant but adjustable rate to a tube 25 that leadsfrom housing 2| By this arrange ent raw materials in the particle form gconstituents of the desired metalmay of electrode II. By properlyadjusting the rates of burnoif of electrode l8 metal of the desiredanalysis may be constantly produced. The rawmaterials in the particleform are usually metallic but in-some cases one or more of theconstituents may be obtained from 'non-metallic raw materiennon-metallic raw materials are used suchraw materials are also meteredthrough one or more of the metering devices. when additions to the fluxare necessary these can also bemade by meteringthrough one of themetering devices.

by member 2:. Member it includes a body portion 21; while bodyporti0n'21 is generally of circular cross-section as shown it may be ofany preferred cross section. Channels 28 and 29 extend laterally frombody portion 21. The side walls of the channels end at a common leveland are united to .top plates 99 and 3|. 92 are united to the top platesand to the walls of the channels to form a depending skirt whichencirclesbodyportion 21. Trunnion pieces 93 are attached to skirt 92, orto body portion 21, so that member 28 may be supported in operation andmay be tilted at the end of the operation to remove the materialtherein. I

' Cylindrical body portion 21 is surrounded by a plurality of coils 9!,similar coils are also provided beneath the bottoms of channels 29 and29,

v with refractory material 25 it is preferable to form the bottom ofbody portion as shown in Fig. 4. In this. figure the bottom of body prtion 21 includes'a central extension 29 of reduced diameter." Extension:9 is enlarged inter mediate its endsto provide one or more corrugations48, one only being shown, The plug 98 employed is of a diameter to fitwithin extension 89 and is united by. weld metal 28 to the 1 bottom ofextension 39. With this arrangement lining 85 will not be damaged whenthe metal in body portion 21 is allowed to cool and solidify at 1 theend of an operation as corrugation 48 will allow plug 38 to move asrequired to relieve the pressure which tends to collapse lining 29.

Channel 28 is so'located that its bottom is a substantial distance belowthe. desired level of the molten metal in the fusion z'one. of channel28is lined by a block ll of refractory material. The sides of channel 28are "lined with refractory blocks- 44. At the discha ge nd of channel.28 is positioned dam block '45 also of refractory material. Block isgenerally triangular in cross-section and on its discharge Skirt pieceswhich are supplied, as through a valve controlled line; with. water orother heat exchange medium.

Coils -94 are perforated to allow the heat ex change'nledium to Jetagainst the surface to be cooled. Coils 24 may be ind vidual coils whosesupply of heat exchange medium is individually controlled or they may beconnected and controlled as a unit.

While the letting of the heat exchange medium on the surfaceto be cooledis at present preferred, a Jacket through which heat exchange medium iscirculated may be sub- The coils are provided as an aid in controllingthe temperature conditions within the fusion zone.

The walls of body portion 21 may be-unlined, in such a case body portion21 is preferably made of a metal .of high heatconductivity, as forinstance, copper. When desired or necessary, the 'walls of body portion21 may be lined with a refractory lining. as. lining 95 of Fig. 4. Inthe latter case body portion 21 may be made of any suitable metal. Whena lining 95 is employed it side has a weir groovelii cut therein whichis shaped to confine the flow of the liquid. metal and to reduce wear ofblock 45 by erosion to a minimum. Erosion of the top of the weir blockwill gradually changethe height of the molten metal in the fusion zone;if the change proceeds far enough the conditions in the fusion zone willbe altered. A constant height of molten metal may easily be maintainedand erosion of block 45 kept to a minimum by positioning a tube 91 inthe-top of block 45, at or adjacent the floor of the top portion ofgroove 46, as shown in Fig. 2, and circulating water or other coolingmedium at a, high rate through the tube. Various heights'of metal may bemaintained in the fusion zone by using dam blocks 45' of differentheights. The molten metal after it leaves groove 46, falls into mold 49,or other receptacle. A blanket of molten flux 58 may be maintained onthe metal in mold 99.

. Channel 29' ordinarily is unlined as thefluxes employed in metalproducing operations generally have a pronounced solvent action on theusual refractory materials. The bottom of channel 29 is somewhat above.the liquid metal level in'the fusion zone so that only flux 5| willmove into it. A metal dam block 52 is positioned ad- 'jacent thedischarge end of channel 29. Block 52 is generally triangular in crosssection and includes an appropriately shaped weir groove 58 throughwhich the flux is adapted to flow. To

is usually preferable to line onlyv thatportion of the fusion zone whichcontains the molten metal as the fluxes employed generally have apronounced solvent action on the refractory material of the lining. Inthe bottom of body portion 21 is provided a metal'plug 38 of preferablythe same analysis as the metal to be produced. The bottom of bodyportion 21is connected by a cable 21'to the other. side of the electriccurrent prevent destruction of block 52 it is cooled by circulating ofwater or other heat exchange medium through tube 54. The circulation ofthe heat exchange medium is controlled by a valve in the inlet side oftube 56. Blocks .52 of various heights may be used.

supp y. .It is preferable as shown, to ground the Skimmers 55 and 55project into channels 28 and 29 respectively. The skimmers aside fromtheir height and width are of identical construction. Each includes ametal block 51 having a bore 58 therein that opens at one end of theblock. A valved line 59 is threaded into the The bottom eteriouslyaffect the metal.

51 and that a substantially continuous jet is produced. The casingmember is preferably made of copper and is brazed or otherwise united toblock 51. A threaded bushing 62 is brazed to casing member SI andreceives the threaded end of outlet pipe 53 through which the water orother heat exchange medium is evacuated. To each end of block 51 isunited a pair of angle pieces 64 having holes accommodation of threadedstuds 65. Nuts 65 are provided for positioning angle pieces 54 atpredetermined levels on studs 55. Studs 55 are carried by strap pieces61 that are united to the top plates 30 and Si. The arrangement just described is such as to permit the rapid positioning, adjustment andremoval of skimmers 55 and 58.

Skimmer 55 serves to separate molten flux from the molten metal beneathit so that when the predetermined level of molten metal has beenobtained in the fusion zone only molten metal can flow into channel 28and over dam block 45. Skimmer 56 serves to separate molten flux fromunfused material and assures that only molten flux will find its wayinto channel 29 and over dam block 52.

Flux 5| protects the metal during its production and refinement anduntil it passes beneath skimmer 55. The molten metal as it flows fromskimmer 55 to mold 49 is exposed to the atmosphere. This exposure isordinarily insuiiicient to del- However, it is sometimes desirable toeliminateeven this limited exposure. In such cases a covering of ceramicmaterial may be provided to cover the metal therein for the from swimmerto the outlet of groove 46; it

may also be desirable to maintain an atmosphere of inert gas betweenthis covering and the molten metal.

In carrying out any particular operation, after the raw materials to beused are selected, the rates of feed of the raw materials to be meteredthrough the metering devices and the rate of feed of hollow electrode l8are determined. The proper settings are made so that in operation therewill be continuously supplied to the are at the end of the hollowelectrode the constituents of the desired metal in the proportionsrequired to produce the predetermined analysis. The various valvescontrolling the flow of water, or other heat exchange medium to coils34, tubes 41 and 54 and skimmers 55 and 58 are then opened. Electrode I8is then fed until it closely approaches block 35 when an arc starter,such as a wad of steel wool is interposed between block 36 and theelectrode. A quantity of. flux, or the ingredients required to producethe flux is passed into member 21. The electric current circuit ofelectrode l8'is then closed.

The initial surge of current destroys the arc starter and establishes an.arc between the end of electrode I8 and block 35. The heat generated bythe arc fuses metal at the end of the elec 'trode, the raw materialssupplied through the electrode, the flux, or flux constituents and metalof block 35. The molten materials form a molten pool of metal over whichis a molten pool of flux.

The molten metals rapidly intermingle to form the desired metal. As thelevel of the molten materials rises molten flux and then molten metalflow into channel 25, when the level of the molten metal reaches thebottom of skimmer 55 the further flow of molten flux into channel 28 isprevented. The molten metal will ultimately rise to the desired level atwhich it will flow over dam block 45 into mold 49 'at a rate equal tothe rate it is produced.- The flux that initially entered channel 28,will quickly be displaced by metal and from thence on only metal willzlow over dam block 45. while this is going on will flow into channel 29and once it rises above the bottom of skimmer 56 only molten flux canpass from the fusion zone to and over dam block 52. In this way unfusedmaterials, which may be flux ingredients or may contain constitutents ofthe desired metal cannot flow out of the apparatus with the excess flux.

Once the liquid metal level has been established it will remainsubstantially: constant throughout the operation. In operations whereinflux additions are made or materials are employed which include elementsthat are removed by the flux the flux level will be substantiallyconstant and any excess flux will pass over darn block 52.

When the melting point of the metal produced is high it is sometimesadvisable to commence the operation with Skimmers 55 and 55 out of theirrespective channels and apply heat into channel 28 until molten materialflows over dam block 45 in order to prevent freezing of the molten metalin channel 28. After a suitable flow of molten metal is obtainedskimmers 55 and 56 -may be quickly positioned. With the skimmers 55 and55 shown and described it is a simple matter to do this.

I claim:

1. In apparatus for producing metal, a crucible member defining afusion, zone wherein molten metal is produced, means for flowing moltenmaterial from said fusion zone to a point I external of said cruciblemember, said molten 2. In apparatus for producing metal, a cruciblemember defining a fusion zone wherein molten metal is produced, achannel member having one end in communication with said fusion zone, arefractory member lining the bottom of said channel member, furtherrefractory members lining the sides of said channel member, a refractorydam element having a generally triangular cross section on saidrefractory member and between said further refractory members, said damelement having a groove in its top and inits discharge side whichdiminishes in cross-section from the entering tothe discharge endthereof, and a tubular metal member extending through said dam element,said tubular member being located in close proximity to the floor ofsaid groove in the top of said Themolten flux I [material in the fusionpredetermined level, a skimmer element having across said channel from,a portion of member adapted to member, means for medium through saidtubular member.

3. In apparatus for producing metal, a cruelble member defining a fusionzone whereinmolten metal is produced beneath a blanket of molten fiux, achannel member having one end a restricted outlet, a casing of metal ofhigh heat conductivity united .to said body member and enclosing saidtubular members, and outlet means in communication. with said fusionzone, a dam element at the other end of saidchannel member' adapted toprevent the level of the molten zone from rising above a metallic wallsextending across said channel member between the ends thereof andprojecting into said channel member a substantial dischamber, and meansfor circulating a cooling medium at a high velocity against the innerface of said walls below and adjacent the level of the top of said damelement.

4. In apparatus for producingmetal, a crucible member defining a fusionzone wherein molten metal is produced beneath a blanket of molten flux,a channel member having one end in communication with said fusion zone,a dam element at the other end of said channel member adapted to preventthe level of the molten material in the fusion zone from rising. above apreskimmer element extending member, a substantial distance below thetopof said' dam element, said skimmer element including metallic walls ofhigh heat conductivity defining an internal chamber, means for jetting acooling medium against the inner face of said walls, and means forremoving the cooling medium from said chamber. v

5. A skimmer adapted for use with molten materials maintained at hightemperatures comprising a body member, a casing member having wallsniade of a metal of high heat conductivity united to said body memberand depending theresaid casing member being adapted in use to contactthe molten materials, cooling medium jetting means carried by said bodymember and. projecting into said casing let a cooling medium against theinner walls of said portion of said casing to said jetting means, andmeans for said medium from said chamber.

6. A skimmer terials maintained at high temperatures, comremovingadapted for use with molten ma- I supplying a cooling medium of saidextension.

movementof the end insaid casing for the evacuation of the coolingmedium. I

-7. In apparatus for producing metal, a crucible member defining afusion zone wherein molten metal is produced beneath a blank of moltenfiux, a channel member having one end in communication with said fusionzone, a dam' element at the other and of said channel member adaptedtoprevent the level of the molten material in the fusion zone from risingabove a predetermined level, a r dvable skimmer element extending acrosssa d tween the ends thereof and projecting into said channel member asubstantial distance below the top of said dam element, and means onsaid crucible member for supporting said skimmer membe:- in saidchannel, said support means including means for adjusting the positionof said skimmer member relative to the bottom of said channel,said-skimmer member including metallic walls and means for cooling saidwalls.

8. In apparatus for producing metal, a metal crucible member having abody portion defining within it-a fusion zone wherein metal is producedby heat supplied through the discharge of electric current, the bottom.of said body portion including an extension of reduced .diam-- eter, ametal electrode member fitting in said extension and projecting intosaid fusion zone, one end of said electrode member being united to andmovable with the end of' said extension,

, and means intermediate'the ends of said extension providing formovement of said electrode membe r and the end of said extensionindependently of remainder of said extension, the bottom and sides ofsaid body non-metallic refractory material.

9. In. apparatus for producing metal, a metal crucible member having abody portion defining within it a fusion zone wherein metal is producedby heat supplied through the discharge of electric current, the side andbottom walls of said body member defining lined with a11131191116128.1110

sionof reduced diameter, and a metal electrode extension and united tothe end of said extension, said extension being enlarged to form acorrugation intermediate -its ends to allow of said extension with saidelement independently of the remainder ROBERT 1:. nor.

electrode channel member beportion being lined with said fusion zonebeing refractory material; the bottom of. said body memberincluding anexten- I

